Self-adjusting clamp-bar for door and furniture clamps.



P. WELKER. SELF ADJUSTING CLAMP BAR ron 1100B AND FURNITURE CLAMPS.APPLICATION FILED PEB.9, 1911. 1,028,923, Patented June 11, 1912.

2 SHEETS-SHEET 1.

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COLUMBIA PLANOURAPH co.,\vAsmNu'roN, D. t.

- F. WELKER.

SELF ADJUSTING CLAMP BAR FOR DOOR AND FURNITURE CLAMPS.

APPLICATION $11.31) $113.9, 1911.

1,028,923, Patented June 11,1912.

2 SHEETS-SHEET 2.

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FREDERICK 'WELKER; 0F WILLIAMSPORT, PENNSYLVANIA.

SELF-ADJUSTING- OLAMP-BAR FOR. DOOR AND FURNITURE CLAIV EPS.

bar which is placed between the work and.

one clamping slab in an ordinary door or furniture clamp, said bar beingprovided with means for adjusting itself longitudinally whereby the workmay automatically square itself while being pressed together; and itconsists mainly in applying to an ordinary door clamp a self-containedintermediate bar provided with anti friction devices which allow it toadjust itself longitudinally, and also in various details, pertaining tosuch construction.

In the drawings, Figure l is a plan view of a clamping slab in a doorclamping machine with the self adjusting bar alongside: Fig. 2 is afront elevation of the bar with portions broken away to show details:Fig. 3 is a cross section of the bar at the dotted line 02 Fig. 2. Fig.4 is a sectional plan view with portions broken away. Fig. 5 is a frontelevation and Fig. 6 a cross section of an equivalent construction,using rollers for the anti-friction members. Fig. 7 is a longitudinalhorizontal section of aportion ofthe length of my device on a largerscale than on Sheet 1; Fig. 8 is on a still larger scale,

and is a central horizontal section showing a single anti-friction unitattached to a bar; Fig. 9 is a like section of the same unit de tachedfrom the bar, the section line being near one edge thereof.

A, Fig. 1, is one of the slabs or platens of an ordinary door orfurniture clamp and may be of any length to accommodate the work to bedone.

B is a bar approximately square in cross section as indicated in Figs. 3and 6, and preferably made of steel. A longitudinal recess D, Fi s. 2,3, 4 and 5 is cut in this bar and in it are located the anti-frictiondevices referred to. In Figs. 2, 3 and 4 these consist of hard steelplates E and F, the first of which lies along the bottom of the recessand in close contact with it, and is held in position by screws or pins2. Upon this hard surface the balls 1, are free to roll be ing held inplace by separators 3 and by Specification of Letters Patent.

Application filed February 9, 1911.

Serial No. 607,661.

springs 4. These springs are slightly compressed between the balls andflanges 5, which are rigidly'attached to the movable plate F, so thatthe balls can roll freely when the plate F moves to right or left underthe pressure of thev work in the clamp, but by means of the springsflthey are returned when the clamping pressure is removed. The balls 1 arepreferably arranged in an upper and a lower ro'w behind each plate F asshown. A separator 3 is situated between saidrows, and other separators3 between the balls of each row. In like manner the movable plate F isreturned by springs 6 which are compressed between the flanges 5, andlugs 7 these latter are attached rigidly to the rear plate E, andthrough an opening in them rods 8 pass freely and are rigidly attachedto the flanges 5 on plate F. Rods Patented June 11, 1912.

8 thus act as guides and retainers against transverse displacement ofplate F.

It will be observed that the above description appliesto only one of theanti-friction elements or units provided on the bar B, but that theseelements are repeated at such intervals along the bar as may be requiredfor strength and durability as indicated in Fig. 1, and it is preferablethat these plates lie neXt to the clampinglslab A, and that the plainface of the bar B lies next to the work W. It is plain that by thisconstruction, no special attachments to the clamping slab are requiredas the bar iself contains all the anti-friction members suitably securedthereto, and it may therefore be removed when not required and used onother clamping machines of a similar character.

tion. An alternate construction is shown in Figs. 5 and 6 in which thesame general arrangement is followed, except that hard steel rollers 9,are used instead of balls, flanges 5 and lugs 7 being provided to takethe resistance of the springs 6 and return the movable plate F to itsnormal position, the springs 4 acting on the rolls in a similar way thatthey act on the balls. When the rollersused are substantially as long asthe width of the groove D and several of them are used, as shown in Fig.5, no special separators are used. I

In this description I have stated that springs 6, return the movableplates to their normal position. What actually occurs is that, onaccount of the friction of the plates F against the slab A, the bar B,moves automatically and is returned to its normal position by saidsprings.

The operation of this intermediate clamping bar is as follows: When thedoors or similar work WV to be pressed together are placed in themachine, one edge of the work comes against one plain clamping slab, andthe other against the self adjusting bar B, which in turn is facedagainst the other slab through the plates F, Figs. 1 and' 3; If theparts of the work should not be laid in exactly square, as is often thecase with doors and similar wide work, the tenons will bring it squareif the door stiles, or one of them, are free to move endWise while thepressure is on; in an ordinary door clamp.

that is impossible on account of the, great friction between the stilesand the clamping slabs; by the interposition of the self adjusting barI3, With the anti-friction plates F, Eand balls orrollers 1, 9, this isovercome, and the tenons or jointed surfaces on the work will move thebar longitudinally sufliciently to square up the Work automatically.

I do not confine myself tothe exact construction of the anti-frictionelements shown in the drawings, because various modifications may bedevisedto accomplish the result described but:

lVhat I claim-as my invention and to secure by Letters Patent is:

1. An independent self-contained clamping device embracing in itsconstruction, a

desire bar having a recess in one face, bearing plates located atintervals therein, antifriction members rolling on said plates, otherbearing plates freely adjustable longitudinally to the bar and acting toretain said anti-friction members and receive the "pressure of the workfor thepurposesset forth.

2. In a door or furniture clamp, a platen, a self adjusting clamping barhaving a longitudinal recess, fixed bearing plates therein,anti-friction members rolling on said plates, movable retaining platesoutside said anti-friction members and extending beyond the edges of therecess, means for holding said outside plates in place, and means withinthe recess for returning said outside plates to normal position afterthe clamp ing operation is completed.

3. In a door or furniture clamp an intermediate self adjusting clampingbar embracing in its construction a longitudinal recess, fixed bearingplates therein, movable outside pressure plates, anti-friction membersbetween said plates, flanges or lugs at the ends of said movable plates,studs secured in said lugs, springs embracing the studs and compressedagainst rigid lugs on the fixed plates, whereby each anti-frictionelement becomes a'unit of construction for the purposes set forth.

In testimony whereof I have subscribed my name in the presence of twoWitnesses.

FREDERICK WELKER.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. 0.

